Production of ammonium nitrate.



new and useful Improvements in the Produc- UNITE STATES AlliN QFFTCEQPRODUCTION OF AMMONIUWI NITRATE.

Specification of Letters Patent.

Patented Dec. 25, 1 906.

Application filed May 1. l9 06. Serial No. 314,700.

To all whom it may concern.-

Be it known that I, VVALTHER FELD, chemist and manufacturer, a subjectof the King of Prussia, German Emperor, residing atHonningen-on-the-Rhine, in the Kingdom of Prussia and German Empire,have invented tion of Ammonium Nitrate, of which the follow'in is aspecification.

Hit erto nitrate of ammonia. has been obtained by neutralizing ammoniawith nitric acid or by subjecting nitrate of soda instead of chlorid ofsoda to the ammonia-soda process by treating a liquor containing bothammonia and. nitrate of soda with gases containing carbonic acid.

According to my invention, nitrate of ammonia is produced by subjectinga nitrate of an alkali or of an alkaline earth to the action of gascontaining both ammonia and carbonic acid in a dilute conditionsuch, forinstance, as coal-gas, coke-oven gas, blast-furnace gas, power-gas, andother gases of distillation.

Hitherto the ammonia from such gases has been absorbed by water, thenthe weak and impure ammonia solution has been concentrated and urifiedby distillation, and then after a sec nd distillation the ammonia hasbeen added toa solution of nitrate of soda or nitrate of soda has beendissolved in a solution containing ammonia, and this solution containiboth ammonia and nitrate of soda has een treated with gases containingcarbonic acid. t By my invention the process is considerably simplifiedby subjecting a nitrate of an alkali or of an alkaline earth (withoutbein previously treated with ammonia alone ano then with carbonic acidalone) directly to the action of gases which contain both ammonia andcarbonic acid, as aforesaid, in great dilution. sides ammonia,sufficient carbonic acid for the treatment of alkaline earths toprecipitate the whole of the alkaline earth in the form of insolublecarbonate in forming soluble nitrate of ammonia, one molecularproportion of carbonic acid to two molecular proportions of ammoniabeing necessary. 11 using a nitrate of an alkali, such as nitrate ofsoda, the gas must contain at least one molecular proportion of carbonicacid to each molecular proportion of ammonia to precipitate the alkalias bicarbonate. If the amount of carbonic acid in the gas be less thanthis,

The said gases as a rule contain, be-- carbonic acid in any form isadded to the gas or the nitrate is alternately or simultaneously treatedwith grs containin both ammonia and carbonic acid and wit gas containingcarbonic acid alone, such as pure carbonicacid gas, or ases which areproducts of combustion, or t 6 like.

The following is an example of how this invention may be performed; butit is to be understood that I do not limit myself to the use of theparticular gas or the particular nitrate mentioned, nor to theproportions given in this example.

In carrying out this invention for example, with nitrate of soda andwith coke-oven gas containing ten grams of ammonia and thirty grams ofcarbonic acid per cubic meterafter tar and water have been se aratedfrom the gas, this is passed over or t ough a concentrated solution ofthe nitrate. I may even add to the saturated solution undissolvednitrate, this bein gradually dissolved in proortion as the sa t insolution is transformed mto nitrate of. ammonia, which is far moreeasily dissolved than are the other nitrates. Byv this treatment I get ahighly-concentrated solution of nitrate of ammonia. The solution istreated with the gas until practicall all the nitrate of soda isconverted into icarbonate of soda and the escaping gas is treated with afresh solution of nitrate of soda in order to absorb all the ammonia andcorresponding carbonic acid from the gas The ammonia and carbonic acidbeing very diluted in the gas the absorption 0 ammonia and carbonic acidtakes place slowly or gradually, and therefore the reaction does notcause such rise of temperature in the solution as would cause theabsorption to be incomplete or cause ammonia already absorbed to bevolatilized. The Water bein separated from the gas before it is passedover or through the solution the solution is not diluted, and thereforethe yield of bicarbonate of soda is high, which is an importantpractical advantage in carrying out the process.

If gases containing sulfureted hydrogen be employed, the solutions willbe contaminated by sulfids. In such cases, therefore, the sulfuretedhydrogen must either be separated from the gas, passing it into contactwith the nitrate of an alkali or of an alkaline earth, or both theammonia and carbonic acid of the gas (before this is passed over orthrough the nitrate solution) are absorbed by a solution of a salt,which does not absorb sul- J fureted hydrogen and which When heatedgives ofi the ammonia and carbonic acid absorbed. Suitable saltsfor thispurpose are salts of magnesia, such as sulfate, chiorid, and the like.in using chlorid of magnesia carbonate of ma nesia and chlorid ofammonia are forme By boiling this sludge ammonia and carbonic acid aredistilled off and passed over or through the solution of the nitrate ofan alkali or of an alkaline earth. in order in this case to obtain theammonia and carbonic acid in a suitablydilutedccondition, air orpurified gases of combustion or the like can be passed through thesludge While it is boiling. @f the gas for dilution so much is used thatthe proportion I of ammonia and carbonic acid in the gas escaping fromthe distilling-vat is such that when the gas is cooled no carbonate ofammonia is precipitated in the pipes leading to the absorber.

I claim as my invention-- 1. The production of nitrate offammonia bysubjecting a nitrate of an alkali to the action of gas containing bothammonia and carbonic acid in a dilute condition.

2. The production of nitrate of ammonia by subjecting a nitrate of analkali to the action of gas containing both ammonia and carbonic acid ina dilute condition, and of carbonic-acid gas.

in testimony whereof I have signed this specification in the presence oftWo subscribmg wltnesses.

WALTHER FELD.

Witnesses:

E/YOLDEMAR HAUPT, iTlENRY HASPER.

